Array of an element

Yep that's correct, the flipflop will become 16 bits wide in that case. In that schematic I didn't use the megawizard to parameterize the flipflop, I just selected it directly and added it so Quartus uses information about what's hooked up to it to figure out how it should be parameterized. If you incorrectly labelled the input and output of that register with different widths then you should get an error or warning depending on which one is wider (I haven't done schematic design in many years so just going by memory).

You probably noticed those wires/buses that are labelled but don't go anywhere. Quartus uses name matching to join nets with the labels that have the same names. If you have used other schematic tools for board design this is typically called an 'alias' and the same rules apply. When I was doing a lot of schematic entry I would use them to keep my schematic clean, otherwise you'll have wires and buses wrapping around blocks which makes it hard to follow sometimes (imagine having 30 clock connections and the mess that would make if you didn't use aliases :))